A completion system installed in a well typically includes flow control devices (such as in the form of valves) to control fluid flow in the well. The fluid flow can include production flow (to produce hydrocarbons or water from a reservoir) and/or injection flow (to inject fluid into a formation). The flow control function in a downhole valve is usually accomplished by using a flow constriction, such as in the form of a nozzle. The flow rate through the valve is regulated by changing the cross-sectional area available to fluid flow. In most downhole applications, the pressure differential across a valve can be relatively high, which can lead to creation of powerful fluid jets output from the valve.
Many valves control fluid flow in a radial direction of a wellbore. Since the available space in a wellbore is relatively limited, the distance between valves and other structures (e.g., tubing, pipe, casing, etc.) is relatively small. Consequently, a relatively powerful jet produced by a valve that impinges upon a downhole structure can cause substantial erosion of the downhole structure. For example, in the injection context, the fluid jet produced by a valve can impinge upon the casing, which can cause erosion of the casing after some amount of time. Erosion of downhole structures can also occur in the production context, where fluid flows from a wellbore annulus into a tubing or pipe.
Conventional techniques of providing erosion control include providing shrouds around a valve to protect a surrounding structure, such as the casing, from a powerful fluid jet. However, shrouds add to the complexity and expense of a tool string that contains the valve.